Adding an



D. WITTNEBERT. ADDING AND suBRAcTlNG MACHINE.

APPLxcMIoN FILED sm. 21, mg. 1 ,949, Patented DGC- 14, 192g.

@M/iii@ UNITED STATES DUKE WITTNEB ERT.

OF DEL RIO,

PATENT OFFICE.

TEXAS.

ADDING ANll SUBTRACTING MACHINE.

Spccitcatmn of Letters Patent.

Patented Dec. 14, 1920.

To all whom it may concern.'

Bc it known that l, DUKE lVrrrNnnnn'r, a` citizen of the United States, residing at Del Rio, in the county of Val Verde and State of Texas, have invented new and useful Improvements in Adding and Subtract ing Machines, of which the following is a specification.

This invention is an improved adding machine which can be also used for subtracting, and which is especially adapted to be attached to one end of a lead pencil, the object ol the invention being to provide a maY chine oi this kind which is extren'iely light in weight, is small and compact, is easy te operate and convenient for any class oi work in addition or subtraction, and which can be readily manufactured at small cost and is simple in construction.

Vith the above and other objects in view, the invention consists in the construction, combination and arrangement of derices hereinafter described and claimed.

In the accompanying drawings Figure l is an elevation, on an enlarged scale, of an adding machine constructed and arranged in accordance with my invention.

Fig. 2 is a similar view of the same with the casing in section.

Fig. 3 is a longitudinal sectional view of the saine.

Figs. 4 and 5 are transverse sectional views of the same.

In the embodiment of my invention, I provide a pair of shafts 1. 2 which are secured in spaced relation by bracesl 3 which are arranged at the ends of said shafts, the said shafts being fixed. A series ol disks or guide wheels 4, 5, 6, 7 and 8 are fixed to the shaft 2 in spaced relation and respectively indicate units. tens, hundreds` thousands and tens oi thousands and are each provided with peripherally arranged numbers from one to nine, as shown. Carrier Wheels 9,10, 11, 12 are arranged for rotation on the shaft 2 and between the disks or guide wheels 4, 5, 6, 7, 8, and each carrier wheel is provided with ten radial openings 13 for the reception of a pencil point or the like, to enable said wheels to be turned. Each carrier Wheel is provided on one side with a radially projecting tappet 14 which is fixed thereto and turns therewith` Each carrier wheel is rovided on the right hand side, which is t e side opposite that on which the tappet 14 is arranged, with twenty spur gear teeth 15. In a recess 15*I intheleft hand'side and periphery of each fixed disk or guide wheel is a small detent gear 16 which is adapt-ed to rotate about its axis.

,l series of registering wheels or disks 1T, 1S, 19, 2O and 421' are mounted on the shaft 1 for independent rotation and' `are arranged in line with the fixed guide wheels or disks and are each peripherally numbered from one to naught,V the `said registering wheels respectively indicating units, tens, hundreds, thousands and tens of thousands. On the left hand side of each of the registering wheels 17, 18, 19 and 2O is a gear of twenty spur teeth 22 which are respectively engaged by the gear or spur teeth of the carrier Wheels 9, 10, 11 and 12, so that the carrier Wheel 9 is geared to the units Wheel 17, the carrier Wheel 10 is geared to the tens wheel 18, the carrier Wheel 11 is geared to the hundreds Wheel 19, and the carrier Wheel 12 is geared to the thousands wheel 20. Each of the wheels 18, 19, 20 and 21 is provided on,A

the right hand side with a series of ten tappets 23 which are parallel and in concentric relation to the shaft 1 and correspond with the peripheral numbers on said wheels and are adapted to be enga ed by the tap pets 14 of the carrier Whee s. The detnt gears 16 in the fixed guide wheels or disks also engage the gears of the registering Wheels. The function of these detent gears is to prevent too free or casual rotation of the registering wheels Without interfering with the necessary step by step rotation of said wheels.

The registering wheels are covered by a substantially semicylindrical casing 24 which has openings 25, 26, 27, 28, 29 on one side through which respectively the peripheral numbers of the registering Wheels may be displayed. At one end of the casing is a socket piece 30 for the reception of one end of a lead pencil or other suitable holder.

In practice, the machine is, preferably,

very small so that it can be conveniently carried on a lead pencil and without intertering with the use of the lead pencil as such but within the scope of the invention the machine may be made of any suitable size and may be made of any suitable material. Preferably, also, to minimize the. weight. the various Wheels or disks may be hollow or spoked.

To add, the appropriate carrier Wheels are turned in one direction and to subtract the cui-rior wheels :ire turned appropriately in the reverse direction. it wil] be under stood that :it mu'h complete rotation of one of tinl (fui-rior wheels the registering wheel to the right thereof und which is geared thereto will he correspondingly turned and the registering wheel to the left thereoi| will be turned through one-tenth of a revolution by the engagement of the tappet i4 with one of the toppets 23. Hence, the naught or ten will be carried from one column into the next higher column throughout the series, as will be understood.

Unie I have herein shown und described n preferred embodiment of my invention, I would have it understood that changes may be made in the forms, proportion and construction of the several parts Without departing from the spirit of my invention and within the scope of the appended claim.

Halvdg thus described my invention, I claim In "1 adding and subtracting machine, the combi ation of a casingl having openings, registqfing Wheels independently revoluble in sai casing opposite said openings and havii`4A`V54 spur gears und also having lateral pi "4 in circular series, fixed disks or guide v 's arranged in spaced relation and each in ei Anement with one of the registering Wheels and each having in its periphery :ind one side a recess, gears arranged and adapted to rotate in sind recess and intermeshed with the spurA -gezirs of the registering Wheels, carrier Wheels revoluble in the spaces between the fixed disks or mide Wheels and having spur gears' intermeshed with those of the registering wheels and also having 'peripheral sockets, :1nd a, tappet el'iri'ied by each carrier wheel for eoperniion with the pins of one registering Wheel.

In testimony whereof I tifiix my si nature.

DUKE VVITTNEB RT. 

